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2 Cognition in Context Can often compensate for physical disabilities by change in environment Wheelchairs Redesigned appliances Cognitive competence also depends on environment Can you cook dinner, given a dead animal, a stone knife, and set of flints?

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3 Social Context The context for cognition involves both the physical and social environments Stability & organization of physical environment may reduce cognitive load Other people (e.g. a spouse) can actively assist in problem solving How can I make coffee? Which way is home?

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4 The $80 Billion Question Can we build computer systems that (like a caregiver) actively assist a person with Alzheimer’s perform the tasks of day-to-day living? Enhance quality of life Prolong aging in place Lessen burden on other caretakers Depression affects 20% of Alzheimer’s patients, but 50% of Alzheimer’s caregivers Crisis in demographics – shortage of caretakers

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7 Example: Activity Compass Help user move between home and community Walking, riding in a car, public transport Predicts where user is going Offers simple directions Detects potential problems Is user on the wrong bus? Is user wandering?

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8 Example: ADL Prompter 1. Joe enters bathroom at 9:00 am. 2. He turns on water, and picks up toothbrush. 3. Nothing happens for 30 seconds. AC system recognizes “tooth brushing” activity has stalled. 4. Prompts Joe to pick up toothpaste. Joe does so and completes task. 5. Joe leaves bathroom with water still running. AC system gently encourages Joe to go back and turn it off.

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13 User Feedback User may deviate from predicted path because System is wrong – need to update model User is in error – confused, forgetful System may ask for user for confirmation “Tap if you’re okay” Balance cost of annoying user vs. probability that user is in danger

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14 Deciding When to Intervene (Horvitz 98) G = prediction that help is needed

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29 Technical Foundations Hidden Markov models Mathematical framework for describing processes with hidden state that must be inferred from observations Hierarchical plan networks Represents how a task can be broken down into subtasks Hierarchical hidden Markov models Key to climbing food-chain!

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30 Key Issue How to go from noisy and incomplete sensor measurements to A meaningful description of what a person is doing “Trying to brush teeth” “Trying to get home” A decision by the system about whether or not to intervene … in a principled and scalable manner!

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31 Interventions Framework allows AC system to predict when a “failure” is likely Different failures have different costs Wandering in bedroom Wandering outside Forgetting to take medicine Forgetting to flush Must avoid: